Research On Composite NC Machining Method For Additive And Subtractive Manufacturing

The technology additive and subtractive manufacturing is a new technology developed gradually in recent years.This technology not only retains the advantages of short development cycle and material saving,but also solves the problems of unsatisfactory dimension accuracy and surface quality by subtractive manufacturing.However,at present,most of the additive and subtractive manufacturing software generate their respective processing codes through the additive or subtractive software,and then generate the additive and subtractive NC processing codes through the subsequent manual fusion.The process is cumbersome.Moreover,this kind of compound processing method mostly does not consider the plan of additive and subtractive manufacturing,which is still difficult to process complex parts.Therefore,this paper deeply studies the method of compound NC machining of additive and subtractive manufacturing,and completes the development of software system of compound NC machining of additive and subtractive manufacturing,and realizes the direct conversion from part model to NC machining code.The main work of this paper is as follows:1.A compound path scanning method for additive manufacturing is proposed.In order to reduce warping deformation and improve forming efficiency,a scanning path algorithm was proposed,which combines boundary outline offset,internal partition line and interlaminar layered orientation.Combining this algorithm with the fused deposition method,additive manufacturing has been successfully realized on 3D printer,which verifies the correctness of the algorithm.This compound algorithm reduces the time of cross-cavity and improves the quality of the incremental forming.2.A method of subtractive manufacturing based on STL data information is proposed.In order to remove the step effect and slag hanging on the side surface of the added parts,the method of subtractive manufacturing path generation for the added parts was studied.The path section method is used to generate the cutter contact trajectory,and the calculation methods of normal vector and curvature of cutter contact at different locations were studied,and the generated cutter contact trajectory was optimized.Five-axis post-processing technology was studied to realize the conversion of tool position file to NC code of subtractive manufacturing.Processing simulation was carried out on Vericut software and the correctness of the algorithm of subtractive manufacturing path generation is verified.3.Design and software development of compound path scheme for additive and subtractive manufacturing.In order to realize the compound NC machining of additive and subtractive manufacturing and give full play to its maximum advantage,the scheme of additive and subtractive manufacturing alternately was designed.Based on VC6.0 as software platform,the software system of additive and subtractive manufacturing based on STL files has been developed,and the direct conversion from STL files of processing parts to NC codes has been realized.Experiments were carried out on the experimental platform of scheme by using the NC code generated by the software,and the correctness of the scheme and software development was verified.